How is ozone formed in the upper atmosphere? What causes its damage?

How is ozone formed in the upper atmosphere? What causes its damage?

Answer:
O2—UV—>O + O
O + 02 —> O3 (ozone)
Certain harmful chemicals such as chlorofluorocarbons (CFCs), are released into the air. These accumulate in the upper atmosphere and react with ozone resulting in reduction of the ozone layer by forming a hole. Thus, ozone layer becomes thinner and gets depleted allowing more ultraviolet rays to pass through the earth’s atmosphere. These radiations are highly damaging to organisms and cause skin cancer, damage to eyes, including increased incidence of cataract and damage to immune system of human beings and other animals.